Currently, as terminal devices such as mobile phones and tablet computers are widely prevalent, screens become main interfaces for human computer interaction, which significantly enhances the convenience of human computer interaction, and gorgeous interfaces also bring ultimate visual experience to people. Using a mobile phone as an example, there are generally several virtual buttons or physical buttons below the screen of the mobile phone. When a user performs a button operation, button backlight is turned on; especially in a relatively dark environment, turning on the button backlight is more helpful in clearly seeing an operated button.
Existing button backlight includes only white light; as a result, display is monotonous, which cannot meet individualized requirements of users.